ambari-server/src/main/java/org/apache/ambari/server/api/AmbariPersistFilter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.ambari.server.api;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.inject.persist.UnitOfWork;

/**
 * Replacement for Guice built-in PersistFilter as PersistService is started on Ambari start
 */
@Singleton
public class AmbariPersistFilter implements Filter {
  private final UnitOfWork unitOfWork;

  @Inject
  public AmbariPersistFilter(UnitOfWork unitOfWork) {
    this.unitOfWork = unitOfWork;
  }

  @Override
  public void init(FilterConfig filterConfig) throws ServletException {
  }

  @Override
  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    unitOfWork.begin();
    try {
      filterChain.doFilter(servletRequest, servletResponse);
    } finally {
      unitOfWork.end();
    }
  }

  @Override
  public void destroy() {
  }
}